Improvement in mitering-machines



UNITED STATES PATENT OFFICE.

GEORGE TRIMBLE, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN MITERING-MA CHINES.

Specification forming part of Letters Patent No. 51,633, dated December19, 1865; antedated December 5, 1865.

To all whom it may concern Be it known that I, GEORGE TRIMBLE, ofPhiladelphia, Pennsylvania, have invented an ImprovedMitering-Instrument; and I do hereby declare the following to be afull,clear, and exact description of the same, reference being had to theaccompanying drawings, and to the letters of reference marked thereon.

My improved mitering-instrument consists of a graduated base, withadjustable blocks, in combination with a vertically-adj ustable framefor guiding the same, the whole being arranged substantially asdescribed hereinafter, so as to afiord facilities for sawing strips ofwood to any desired angle.

In order to enable others to make and use my invention, I will nowproceed to describe its construction and operation.

On reference to the accompanying drawings, which form part of thisspecification, Figure 1 is a front view, and Fig. 2 a plan view of myimproved mitering-instrument.

A is the base of the instrument, and to this base are secured the twostandards B and B, which are strengthened by the braces m m. Anadjustable frame is adapted to these standards, the frame consisting ofthe two boards H and H, connected together by the end pieces, a a, andcentral piece, D, an angular projection, D, being secured to the underside of the frame, and a slot, 4;, just wide enough to admit an ordinarysaw-blade being out in this projection and into the frame, which is sofitted to the standards that it can be adjusted in a vertical directiononly.

On the base of the machine are marked one or more semicircles from acentral point, as, and from the latter to the circumference of thecircle are drawn a series of radial lines, 3

F and F are guide-pieces each having a perfectly straight and true faceagainst which to rest the piece of wood to be sawed, these guidepiecesbeing secured to the base by set-screws h, which pass freely throughsemicircular openings a in the said base, and screw into aplate beneaththe same.

A line y, Fig. 2, drawn through the center as on the base A, andcoinciding with the line which represents the slot '17 in the adjustableframe, and in its projection D is the initial line from which all othergraduating lines are measured and by which they are determined, and isthe line on which the saw, guided by the slot 1;, must cut the wood heldon the base.

Supposing it to be desirable to sever a number of pieces of wood,M--such, for instance, as the molding for a picture frame-at an angle offorty-five degrees. The screws h h are first loosened and theguide-pieces F and F so adjusted that their true faces shall coincide,one with the line marked 45 on one side of the line j, and the otherwith the corresponding graduation on the opposite side of the said line.The guide-pieces are then secured by tightening the screws and theinstrument is ready for use. The strip of wood is held against the trueside of one of the guide-pieces, while it is severed by the saw, thelatter being guided by the slot n, so that the severed end will be at anangle of forty-five degrees with the side of the strip held against theguide-piece.

Either of the guide-pieces may be used, as may suit the convenience ofthe operator.

The frame for guiding the saw can be readily adjusted vertically to suitthe thickness of wood to be severed by the saw. The radial graduationson the base may be distinguished with whatever figures or letters may bedeemed appropriate.

The projection D may be made of any hard wood or metal, so that the slot1; cannot be readily made larger by the friction of the sawblade.

I claim as my invention, and desire to secure by Letters Patent-- 0 Thegraduated base A and its adjustable guide-pieces F and F, in combinationwith the vertically-adjustable frame and its slot for guiding the saw,the whole being constructed, arranged, and operating substantially asand for the purpose herein set forth.

In testimony whereofIhave signed my name to this speeificationin thepresence of two subscribing witnesses.

GEO. TRIMBLE.

Witnesses:

CHARLES EbFosrna, JOHN WHITE.

